Antifungal activity of plant essential oils and Pseudomonas chlororaphis strains against Cercospora beticola Sacc.

Leaf spot disease caused by Cercospora beticola Sacc. is the most destructive foliar of beet. leaf controlled primarily fungicides because non-chemical alternatives do not provide commercially viable control. One ways reducing chemical application use different essential oils (EOs) or antagonistic plant growth-promoting rhizobacteria (PGPB). This study evaluates several EOs and PGPB belonging to Pseudomonas chlororaphis as possible control agents this pathogen. Antifungal properties were determined in vitro microdilution method against five C. monosporial isolates originated from locality Brus, Serbia (53?53? N, 21?04?E 429 m above sea level) using medicinal plants: Turkish pickling herb (Echinophora tenuifolia), oregano (Origanum vulgare), basil (Ocimum basilicum), myrtle (Myrtus communis) obtained a hydro-distillation method. All tested displayed some antifungal activity fungal isolates. Origanum vulgare EO demonstrated strongest (MIC - 0.0055?0.0051mg/mL), Ocimum basilicum slightly lower 0.075?0.045mg/mL), followed Myrtus communis 0.775?0.045 mg/ mL) Echinophora tenuifolia 7.75?4.5 mg/mL). Five P. strains exhibited effect beticola. Overnight culture (ONC) strain E65 induced highest percentage inhibition (75.8%), N3 (72.0%). A cell-free supernatant (CFS) CFS treated with EDTA (CFS-EDTA) these showed similar 60.2 56.0%, both suppressed growth. M1 K113 also reduced growth 67-70% ONC between 48-57% fractions. The L1 B25 60% 50% CFS. lowest (~40%) CFS-EDTA heat-treated (HT-CFS) was recorded for B25, which used reference strain. susceptible all selected E25, N3, M1, vitro, making them promising agent. It recommended that findings should be field conditions.